Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay,Bahia, Brazil using HG-AFS

This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10 % (m/v) (1.0 and 2.0 ml) and concentration of hydrochloric acid (3.0 and 6.0 mol L^?1) were evaluated. The best results were obtained using 3 mL of HCl (6 mol L^?1) and 1 mL of KBr 10 % (m/v), followed by 30 min of prereduction for the volume of 1 mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21 μg kg^?1, respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23?±?0.02 to 3.70?±?0.27 mg kg^?1 for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples.     

Human responses to social-ecological traps

Social-ecological (SE) traps refer to persistent mismatches between the responses of people, or organisms, and their social and ecological conditions that are undesirable from a sustainability perspective. Until now, the occurrence of SE traps is primarily explained from a lack of adaptive capacity; not much attention is paid to other causal factors. In our article, we address this concern by theorizing the variety of human responses to SE traps and the effect of these responses on trap dynamics. Besides (adaptive) capacities, we theorize desires, abilities and opportunities as important additional drivers to explain the diversity of human responses to traps. Using these theoretical concepts, we construct a typology of human responses to SE traps, and illustrate its empirical relevance with three cases of SE traps: Swedish Baltic Sea fishery; amaXhosa rural livelihoods; and Pamir smallholder farming. We conclude with a discussion of how attention to the diversity in human response to SE traps may inform future academic research and planned interventions to prevent or dissolve SE traps.     

Evaluating the impact of interdisciplinary networking in environmental geochemistry and health: reviewing SEGH conferences and workshops

The Society for Environmental Geochemistry and Health (SEGH) is a forum for multidisciplinary interaction relating the geochemical environment to health. With national funding, SEGH identified collaborative opportunities through the MULTITUDE series of workshops (2007–2011). We reviewed the meetings by electronic questionnaire (39?% response). Smaller meetings saw most returning delegates, suggesting networking and personal interaction is a key positive feature of SEGH; 31?% of practitioners and 25?% of academics participated in more than one meeting. Collaboration between SEGH participants resulted in joint funding (13 academics, 4 practitioners, 1 other) and joint papers (19, 5, 3). Evidence of behavioural change was seen in comments in five themes regarding the impacts of the conferences: support for current direction; impact on education practice (academics); new approaches; networking; multidisciplinary work. Multidisciplinary meetings and resulting networking were seen as having real value by many respondents, who encouraged further active pursuit of these activities. SEGH is eager to continue these activities which transform research, education and practice, resulting in a better understanding of the structure and processes comprising the broad geochemical environment on health. Comments showed the value and strength of small, well-organised conferences, bringing together a mixed group of disciplines, both research and applied, in a relaxed atmosphere. The absence of serious negative critique along with clear, positive comments suggests that there is a substantial level of support for, and even pleasure in, SEGH multidisciplinary conferences and workshops over the past years. It is encouraging that annual European conferences are viewed as such a positive achievement.     

Identification of copper sources in urban surface waters using the principal component analysis based on aquatic parameters

The goal of this work was to identify the sources of copper loads in surface urban waters using principal component analysis under the aquatic parameters data evaluation approach. Water samples from the Irai and Iguacu rivers were collected monthly during a 12-month period at two points located upstream and downstream of a metropolitan region. pH, total alkalinity, dissolved chloride, total suspended solids, dissolved organic matter, total recoverable copper, temperature, and precipitation data provided some reliable information concerning the characteristics and water quality of both rivers. Principal component analysis indicated seasonal and spatial effects on copper concentration and loads in both environments. During the rainy season, non-point sources such as urban run-off are believed to be the major source of copper in both cases. In contrast, during the lower precipitation period, the discharge of raw sewage seems to be the primary source of copper to the Iguacu River, which also exhibited higher total metal concentrations.     

Methodology of CO2 emission evaluation in the life cycle of office building façades

The construction industry is one of the greatest sources of pollution because of the high level of energy consumption during its life cycle. In addition to using energy while constructing a building, several systems also use power while the building is operating, especially the air-conditioning system. Energy consumption for this system is related, among other issues, to external air temperature and the required internal temperature of the building. The façades are elements which present the highest level of ambient heat transfer from the outside to the inside of tall buildings. Thus, the type of façade has an influence on energy consumption during the building life cycle and, consequently, contributes to buildings' CO₂ emissions, because these emissions are directly connected to energy consumption. Therefore, the aim is to help develop a methodology for evaluating CO₂ emissions generated during the life cycle of office building façades. The results, based on the parameters used in this study, show that façades using structural glazing and uncolored glass emit the most CO₂ throughout their life cycle, followed by brick façades covered with compound aluminum panels or ACM (Aluminum Composite Material), façades using structural glazing and reflective glass and brick façades with plaster coating. On the other hand, the typology of façade that emits less CO₂ is brickwork and mortar because its thermal barrier is better than structural glazing façade and materials used to produce this façade are better than brickwork and ACM. Finally, an uncertainty analysis was conducted to verify the accuracy of the results attained.     

Evolving Pb isotope signatures of London airborne particulate matter (PM 10)-constraints from on-filter and solution-mode MC-ICP-MS

Pb isotope compositions of biologically significant PM(10) atmospheric particulates from a busy roadside location in London UK were measured using solution- and laser ablation-mode MC-ICP-MS. The solution-mode data for PM(10) sampled between 1998-2001 document a dramatic shift to increasingly radiogenic compositions as leaded petrol was phased out. LA-MC-ICP-MS isotope analysis, piloted on a subset of the available samples, is shown to be a potential reconnaissance analytical technique. PM(10) particles trapped on quartz filters were liberated from the filter surface, without ablating the filter substrate, using a 266 nm UV laser and a dynamic, large diameter, low-fluence ablation protocol. The Pb isotope evolution noted in the London data set obtained by both analytical protocols is similar to that observed elsewhere in Western Europe following leaded petrol elimination. The data therefore provide important baseline isotope composition information useful for continued UK atmospheric monitoring through the early 21(st) century.     

韶山旅游目的地形象感知研究——基于网络游记的内容分析

通过收集网络文本分析游客对旅游目的地形象的评价和感受,运用数据挖掘的手段得到游客感知目的地形象的属性与特征,已成为旅游形象研究的重要途径。本研究以携程旅行网(www.ctrip.com)上发表的韶山游记作为样本,使用Rost Content Mining内容挖掘软件得到游客感知的韶山旅游目的地形象的属性特征,运用内容分析法,建立分析类目。在此基础上,分别对建立的四个分析类目进行分析,探索游客对韶山旅游目的地形象的感知,并就游客对韶山旅游目的地形象的感知进行归纳和分析,由此,得出互联网传播的游客对韶山旅游目的地形象感知的结论。     

Sperm competition and ejaculate investment in red squirrels (<Emphasis Type="Italic">Tamiasciurus hudsonicus</Emphasis>)

Sperm competition is widespread in mammals and occurs when ejaculates from two or more males compete within the female’s reproductive tract to fertilize the ova. Enlarged testes are associated with sperm competition because they produce sperm, but the accessory glands produce fluids and proteins that are also important for fertilization success. Sperm morphology can also have consequences for fertilization success because of its influence on sperm motility. Red squirrels engage in multiple mating, and thus sperm competition is likely. Here, we assess levels of multiple paternity in a natural population of red squirrels, test the prediction that testis size is correlated with size of the accessory glands and sperm morphometry, and test the prediction that ejaculate investment is condition-dependent. Five of six litters (83%) showed evidence of multiple paternity, indicating that sperm competition is likely to have occurred. Testis size was correlated with the size of all three accessory glands (prostate, seminal vesicle, epididymides), and there was a generally positive relationship between the size of the accessory glands and sperm length. Sperm morphology showed significant variation in size and shape among individual male squirrels. There was no evidence of condition dependence of testis size or the size of the accessory glands, but sperm midpiece length was negatively related to body condition. Further work should include determining the fitness consequence of variation in sperm morphometry, testis size, and accessory gland size, and determining the effects of variation in ejaculate investment on sperm motility.